Channel division control equipment of the ISDN primary rate interface circuit

Abstract

An ISDN primary rate interface circuit having a plurality of communication channels, includes a channel division controller. According to predetermined conditions, the channel division controller selects a communication channel out of the plurality of communication channels when generating or receiving a call. The channel division controller provides private branch exchange by enabling allocation of the selected communication channel to an extension group according to a predetermined condition when generating or receiving the call.

What is claimed is:  
     
       1. An ISDN primary rate interface circuit, comprising: 
       a plurality of communication channels;  
       a control channel; and  
       a channel division controller for private branch exchange having a plurality of extensions and being connected to at least one ISDN primary rate interface unit, said channel division controller including:  
       a memory unit which stores selection information for determining conditions for using each of said plurality of communication channels, and  
       communication channel selecting means for controlling individually each of said plurality of communication channels by selecting one of said plurality of communication channels of said ISDN primary rate interface circuit as an originating communication channel based on an extension group number which generates a call and said selection information when a call is generated to said ISDN primary rate interface unit from one of said plurality of extensions.  
     
     
       2. An ISDN primary rate interface circuit, comprising: 
       a plurality of communication channels;  
       a control channel; and  
       a channel division controller for private branch exchange having a plurality of extensions and being connected to at least one ISDN primary rate interface unit, said channel division controller including:  
       a memory unit which stores selection information for determining conditions for selecting each of said plurality of communication channels, and  
       communication channel selecting means for controlling individually each of said plurality of communication channels by selecting a communication channel out of said plurality of communication channels of said ISDN primary rate interface as a receiving communication channel based on said selection information and a destination number extracted from a call setting message notified from said control channel when receiving a call from said ISDN primary rate interface unit.  
     
     
       3. An ISDN primary rate interface circuit, comprising: 
       a plurality of communication channels;  
       a control channel; and  
       a channel division controller for private branch exchange having a plurality of extensions and being connected to at least one ISDN primary rate interface unit, said channel division controller including:  
       a memory unit which stores selection information for determining conditions for using each of said plurality of communication channels, and  
       communication channel selecting means for controlling individually each of said plurality of communication channels by selecting a communication channel out of said plurality of communication channels of said ISDN primary rate interface as a receiving communication channel by referring to said selection information when receiving a call when no destination number is notified from said ISDN primary rate interface unit.